Tuesday, March 18, 2008

The Bioengineering of the Future

What is Bioengineering?

Bioengineering is what you do with biotechnology. Biotechnology is what you get from studying and learning how to manipulate biology. It has been known for more than a hundred years that life is basically a machine which takes in fuel and performs work. This machine is remarkable in that it arose through variation and selection from a very primitive self replicating molecule. The closest analogue of this molecule present in our contemporary biology is the ribosome. It has been found that this ribosome consists, in part, of a strand of RNA. Inside the nucleus of a human cell there are twenty two pairs of chromosomes and either another pair or two different. These, as you are probably tired of hearing, are mostly DNA. In our cells is also an organelle which is called a mitochondria. This organelle was, once, a separate life-form. It evolved separately from the type of cells that make up most of our body and its internal structure is significantly different from the cell it is now a part of. These mitochondria have their own DNA but have come to live within our cells as symbiotes. These scientific findings will underlie the rest of this essay.

What is the significance of DNA? It's just a molecule, right? Yes it is. That is exactly what it is. It has no magical properties whatsoever. Science fiction notions of being able to mutate an adult human by changing their DNA to that of another species, perhaps, would not have any morphological change on the person because there is not, yet at least, a gene that can reshape bone. Most random gene changes result in some kind of disease such as cancer. This should seem weird to you. I am talking about changing a DNA molecule but I'm not suggesting that it becomes anything other than a DNA molecule. I mean changing your garden variety molecule by changing even a single bond usually makes something totally different. What is DNA that it is different? For one thing DNA is actually a family of molecules composed of adenine, thymine, cystine, and guinine. RNA uses a molecule called uracil in place of thymine. A strand of DNA is a linked chain of any number of any combination of those four "base pairs". When we talk about modifying DNA we are talking about rearranging sequences of base pairs.

The DNA molecule serves a function no different from the hard drive on your computer. It stores information. The three billion year history of the DNA molecule is a testament to its effectiveness as a storage medium. RNA is more like your computer's working memory. It is natural to consider the act of designing a DNA strand in the same way we would consider the act of writing a program for a computer. A bioengineer, or as it was put in Blade Runner, a genetic designer, is a DNA programmer. I am trying to express these ideas in these terms because a certain mysticism has arisen around DNA that needs to be dispelled before we can consider the questions of what we might be able, or want, to do with our newfound ability to manipulate it.


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